KR20180112214A - Apparatus and method of prevention of Ack/Nack collision corresponding DL data channel for processing time reduction - Google Patents

Abstract

The present invention provides a solving method for an ack/nack collision problem which occurs in n+3, n+4 PDSCH scheduling discussed in a processing time reduction field based on a TTI of 1 ms. In addition, provided are an ack/nack linkage setting method and a specific operating method of a PUCCH to prevent a multi-terminal from simultaneously colliding with uplink ack/nack for n+3, n+4 PDSCHs.

Description

[0001] The present invention relates to a method and a device for preventing downlink data channel Ack / Nack collision for a sTTI,

The present invention proposes a method for preventing Ack / Nack collision between multiple users that occurs when a PDSCH is transmitted when a processing time reduction service is performed in a 3GPP LTE / LTE-A system.

One embodiment provides a method for preventing downlink data channel Ack / Nack collision for a sTTI, comprising: allocating a PUCCH resource for a terminal having an (N + 4) processing time; Allocating a PUCCH resource for a UE having a (N + 3) processing time to a PUCCH resource for a terminal having a (N + 3) processing time; and assigning a specific shift value to RNC signaling The method comprising the steps of:

Figure 1 illustrates eNB and UE processing delays and HARQ RTT.
FIG. 2 shows a resource mapping per PRB in one subframe.
FIG. 3 shows PHICH processing (Normal CP case in LTE / LTE-A).
4 shows a legacy PUCCH uplink structure.
5 is a conceptual diagram of the configuration of a Legacy PUCCH.
6 shows an example of PDSCH and PUCCH linkage setting between terminals with different processing time.
7 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.
FIG. 8 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Herein, the MTC terminal may mean a terminal supporting low cost (or low complexity) or a terminal supporting coverage enhancement. In this specification, the MTC terminal may mean a terminal supporting low cost (or low complexity) and coverage enhancement. Alternatively, the MTC terminal may refer to a terminal defined in a specific category for supporting low cost (or low complexity) and / or coverage enhancement.

In other words, the MTC terminal in this specification may mean a newly defined 3GPP Release-13 low cost (or low complexity) UE category / type for performing LTE-based MTC-related operations. Alternatively, the MTC terminal may support enhanced coverage over the existing LTE coverage or a UE category / type defined in the existing 3GPP Release-12 or lower that supports low power consumption, or a newly defined Release-13 low cost low complexity UE category / type.

The wireless communication system in the present invention is widely deployed to provide various communication services such as voice, packet data and the like. A wireless communication system includes a user equipment (UE) and a base station (BS, or eNB). The user terminal in this specification is a comprehensive concept of a terminal in wireless communication. It is a comprehensive concept which means a mobile station (MS), a user terminal (UT), an SS (User Equipment) (Subscriber Station), a wireless device, and the like.

A base station or a cell generally refers to a station that communicates with a user terminal and includes a Node-B, an evolved Node-B (eNB), a sector, a Site, a BTS A base transceiver system, an access point, a relay node, a remote radio head (RRH), a radio unit (RU), and a small cell.

That is, the base station or the cell in this specification is interpreted as a comprehensive meaning indicating a partial region or function covered by BSC (Base Station Controller) in CDMA, NodeB in WCDMA, eNB in LTE or sector (site) And covers various coverage areas such as megacell, macrocell, microcell, picocell, femtocell and relay node, RRH, RU, and small cell communication range.

Since the various cells listed above exist in the base station controlling each cell, the base station can be interpreted into two meanings. i) the device itself providing a megacell, macrocell, microcell, picocell, femtocell, small cell in relation to the wireless region, or ii) indicating the wireless region itself. i indicate to the base station all devices that are controlled by the same entity or that interact to configure the wireless region as a collaboration. An eNB, an RRH, an antenna, an RU, an LPN, a point, a transmission / reception point, a transmission point, a reception point, and the like are exemplary embodiments of a base station according to a configuration method of a radio area. ii) may indicate to the base station the wireless region itself that is to receive or transmit signals from the perspective of the user terminal or from a neighboring base station.

Therefore, a base station is collectively referred to as a base station, collectively referred to as a megacell, macrocell, microcell, picocell, femtocell, small cell, RRH, antenna, RU, low power node do.

Herein, the user terminal and the base station are used in a broad sense as the two transmitting and receiving subjects used to implement the technical or technical idea described in this specification, and are not limited by a specific term or word. The user terminal and the base station are used in a broad sense as two (uplink or downlink) transmitting and receiving subjects used to implement the technology or technical idea described in the present invention, and are not limited by a specific term or word. Here, an uplink (UL, or uplink) means a method of transmitting / receiving data to / from a base station by a user terminal, and a downlink (DL or downlink) .

There are no restrictions on multiple access schemes applied to wireless communication systems. Various multiple access schemes such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal Frequency Division Multiple Access (OFDMA), OFDM-FDMA, OFDM- Can be used. An embodiment of the present invention can be applied to asynchronous wireless communication that evolves into LTE and LTE-advanced via GSM, WCDMA, and HSPA, and synchronous wireless communication that evolves into CDMA, CDMA-2000, and UMB. The present invention should not be construed as limited to or limited to a specific wireless communication field and should be construed as including all technical fields to which the idea of the present invention can be applied.

A TDD (Time Division Duplex) scheme in which uplink and downlink transmissions are transmitted using different time periods, or an FDD (Frequency Division Duplex) scheme in which they are transmitted using different frequencies can be used.

In systems such as LTE and LTE-advanced, a standard is constructed by configuring uplink and downlink based on a single carrier or carrier pair. The uplink and the downlink are divided into a Physical Downlink Control Channel (PDCCH), a Physical Control Format Indicator CHannel (PCFICH), a Physical Hybrid ARQ Indicator CHannel, a Physical Uplink Control CHannel (PUCCH), an Enhanced Physical Downlink Control Channel (EPDCCH) Transmits control information through the same control channel, and is configured with data channels such as PDSCH (Physical Downlink Shared CHannel) and PUSCH (Physical Uplink Shared CHannel), and transmits data.

On the other hand, control information can also be transmitted using EPDCCH (enhanced PDCCH or extended PDCCH).

In this specification, a cell refers to a component carrier having a coverage of a signal transmitted from a transmission point or a transmission point or transmission / reception point of a signal transmitted from a transmission / reception point, and a transmission / reception point itself .

The wireless communication system to which the embodiments are applied may be a coordinated multi-point transmission / reception system (CoMP system) or a coordinated multi-point transmission / reception system in which two or more transmission / reception points cooperatively transmit signals. antenna transmission system, or a cooperative multi-cell communication system. A CoMP system may include at least two multipoint transmit and receive points and terminals.

The multi-point transmission / reception point includes a base station or a macro cell (hereinafter referred to as 'eNB'), and at least one mobile station having a high transmission power or a low transmission power in a macro cell area, Lt; / RTI >

Hereinafter, a downlink refers to a communication or communication path from a multipoint transmission / reception point to a terminal, and an uplink refers to a communication or communication path from a terminal to a multiple transmission / reception point. In the downlink, a transmitter may be a part of a multipoint transmission / reception point, and a receiver may be a part of a terminal. In the uplink, the transmitter may be a part of the terminal, and the receiver may be a part of multiple transmission / reception points.

Hereinafter, a situation in which a signal is transmitted / received through a channel such as PUCCH, PUSCH, PDCCH, EPDCCH, and PDSCH is expressed as 'PUCCH, PUSCH, PDCCH, EPDCCH and PDSCH are transmitted and received'.

In the following description, an indication that a PDCCH is transmitted or received or a signal is transmitted or received via a PDCCH may be used to mean transmitting or receiving an EPDCCH or transmitting or receiving a signal through an EPDCCH.

That is, the physical downlink control channel described below may mean a PDCCH, an EPDCCH, or a PDCCH and an EPDCCH.

Also, for convenience of description, the PDCCH, which is an embodiment of the present invention, may be applied to the PDCCH, and the PDCCH may be applied to the portion described with the EPDCCH.

Meanwhile, the High Layer Signaling described below includes RRC signaling for transmitting RRC information including RRC parameters.

The eNB performs downlink transmission to the UEs. The eNB includes a physical downlink shared channel (PDSCH) as a main physical channel for unicast transmission, downlink control information such as scheduling required for reception of a PDSCH, A physical downlink control channel (PDCCH) for transmitting scheduling grant information for transmission in a Physical Uplink Shared Channel (PUSCH). Hereinafter, the transmission / reception of a signal through each channel will be described in a form in which the corresponding channel is transmitted / received.

[Latency reduction in RAN1 ]

The Latency reduction Study Item was approved at RAN plenary # 69 meeting [1]. The main purpose of latency reduction is to standardize shorter TTI operations to foster TCP throughput [2]. For this, performance verification for short TTI has already been performed in RAN2 [2].

Potential impacts and studies related to RAN1 are performed in the following ranges [1]:

o Assessment of impact and performance of TTI lengths between 0.5ms and one OFDM symbols, taking into account the impact of reference signals and physical layer control signaling

o backwards compatibility shall be preserved (thus allowing normal operation of pre- Rel 13 UEs on the same carrier);

Latency reduction can be achieved by the following physical layer techniques:

- short TTI

- reduced processing time in implementation

- new frame structure of TDD

Additional agreements at the 3GPP RAN WG1 # 84 meeting are as follows.

Agreements:

● Following design assumptions are considered:

     o No shortened TTI spans over subframe boundary

    o At least for SIBs and paging, PDCCH and legacy PDSCH are used for scheduling

● The potential specific impacts for the followings are studied

     o UE is expected to receive an SDSCH at least for downlink unicast

           ■ sPDSCH refers PDSCH carrying data in a short TTI

     o UE is expected to receive PDSCH for downlink unicast

           ■ FFS whether a UE is expected to receive both PDSCH and PDSCH for downlink unicast simultaneously

     o FFS: The number of supported short TTIs

     o If the number of supported short TTIs is more than one,

Agreements:

● Following design assumptions are used for the study

     o From eNB perspective, existing non-sTTI and sTTI can be FDMed in the same subframe in the same carrier

           ■ FFS: Other multiplexing method (s) with existing non-sTTI for UE supporting latency reduction features

Agreements:

● In this study, the following aspects are assumed in RAN1.

     o PSS / SSS, PBCH, PCFICH and PRACH, Random access, SIB and Paging procedures are not modified.

● Following aspects are further studied in the next RAN1 meeting

     o Note: The study is not limited to them.

     o Design of sPUSCH DM-RS

           ■ Alt.1: DM-RS symbol shared by multiple short-TTIs within the same subframe

           ■ Alt.2: DM-RS contained in each sPUSCH

     o HARQ for SPUSCH

           ■ Whether / how to realize asynchronous and / or synchronous HARQ

     o The sTTI operation for Pcell and / or SCells by (e) CA in addition to non- (e) CA case

Basically, in the average down-link latency calculation, the latency is calculated according to the following procedure [3].

The following is the same approach as in section B.2.1 in 3GPP TR 36.912, the LTE U-plane one-way latency for a scheduled UE consisting of fixed node processing delays and 1 TTI duration for transmission as shown in Figure 1 below. Assuming the processing times can be scaled by the same factor of TTI reduction keeping the same number of HARQ processes, the one way latency can be calculated as

D = 1.5 TTI + 1 TTI + 1.5 TTI UE + n * 8 TTI (HARQ retransmissions)

    = (4 + n * 8) TTI.

Considering a typical case where there would be 0 or 1 retransmission, and assuming error probability of the first transmission to be p, the delay is given by

D = (4 + p * 8) TTI.

So, for 0% BLER, D = 4 * TTI,

And for 10% BLER, D = 4.8 * TTI.

Average UE  initiated UL transmission latency calculation

Assume UE is in connected / synchronized mode and wants to do UL transmission, e.g., send to TCP ACK. The following table shows the steps and their corresponding contribution to the UL transmission latency. To be consistent in comparison of DL and UL, we add the eNB processing delay in the UL after the UL data is received by the eNB (step 7).

In the table above, steps 1 and 4 and half of the step 5 are assumed to be due to SR, and the rest is assumed to be shown in Table 4.

Resource mapping of short TTI  [3]

In Figure 2 the resource map above is the legacy resource mapping per PRB in one subframe, considering 2 Antenna ports and 2 OFDM symbols control field. In Figure 2 the resource map below is the short TTI resource mapping, considering 2 OFDM symbols used for the control field in order to ensure the backward compatibility. The loss rates (L _legacy , eg 5% - 50%) of the PHY layer are short TTI duration are assumed.

TBS Calculation of short TTI

According to the present invention, the PDSCH is calculated as follows:

For different short TTI duration, The TBS of short TTI PDSCH is calculated as the following table:

[Existing PHICH ]

The DL control channel that sends a response to the PUSCH reception to the terminal is the PHICH. The eNB is operating the PHICH for the purpose of transmitting Ack / Nack for the uplink data channel to the corresponding UE. Bit information '1' or '-1' indicating Ack or Nack is spread in an orthogonal code according to the procedure of FIG. 3 and is mapped to Physical 12 REs.

로 표현되는데, 그룹 내에 orthogonal 시퀀스를

라 하고, 시퀀스들이 multiplexing되는 RE set을

라 한다. 여기에서 PHICH는 PUSCH의 Lowest PRB index(

)와 UL DMRS(

)의 cyclic shift value를 기준으로 implicit하게 결정된다. 이하 구체적인 설명은 아래를 참조한다.Here, the PHICH resource allocated to the UEs is

, Where an orthogonal sequence in the group

And the RE set in which the sequences are multiplexed

. Here, PHICH is the Lowest PRB index of the PUSCH (

) And UL DMRS (

) Is cyclically determined based on the cyclic shift value. See below for a detailed description.

where

is the PHICH group number and

is the orthogonal sequence index within the group as defined by:The PHICH resource is identified by the index pair

where

is the PHICH group number and

is the orthogonal sequence index within the group as defined by:

where

is mapped from the cyclic shift for DMRS field (according to Table 9.1.2-2) in the most recent PDCCH/EPDCCH with uplink DCI format [4] for the transport block(s) associated with the corresponding PUSCH transmission.

shall be set to zero, if there is no PDCCH/EPDCCH with uplink DCI format for the same transport block, and

The PDCCH / EPDCCH with uplink DCI format [4] for the transport block (s) associated with the corresponding PUSCH transmission is shown in Table 9.1.2-2.

PDCCH / EPDCCH with uplink DCI format for the same transport block, and

if the initial PUSCH for the same transport block is semi-persistently scheduled, or

if the initial PUSCH for the same transport block is semi-persistently scheduled, or

if the initial PUSCH for the same transport block is scheduled by the random access response grant .

if the initial PUSCH for the same transport block is scheduled by the random access response grant.

is the spreading factor size used for PHICH modulation as described in subclause 6.9.1 in [3].

The spreading factor is used for PHICH modulation as described in subclause 6.9.1 in [3].

where

is the lowest PRB index in the first slot of the corresponding PUSCH transmission

where

is the lowest PRB index in the first slot of the corresponding PUSCH transmission

is the number of PHICH groups configured by higher layers as described in subclause 6.9 of [3],

 is the number of PHICH groups configured as higher layers as described in subclause 6.9 of [3],

[Existing PUCCH ]

The DL control channel through which the UE sends a response to the PDSCH reception is the PUCCH. The UE uses various formats of PUCCH format to transmit Ack / Nack and CQI information for the downlink data channel to the eNB.

The conventional LTE / LTE-A frame structure (TTI = 1 ms = 14 OFDM symbols) performs slot based PUCCH hopping as shown in FIG. This PUSCH hopping increases the frequency diversity of the PUCCH and consequently increases the coverage of the PUCCH. This is because basically the same signal or one information sequence is transmitted through different frequency bands, so that there is a gain to obtain diversity.

In transmitting an A / N from an existing PUCCH, resource allocation is applied by OCC (spreading) + CS (cyclic shift) on the basis of format 1a and 1b. As shown in FIG. 5, the existing PUCCH is set to 3 symbols RS and 4 symbols A / N on a slot basis.

In this proposal, CS-based A / N multiplexing resource allocation of the Zadoff-Chu (ZC) sequence excluding the existing OCC is proposed considering that the number of symbols of the sPUCCH is reduced. Unlike the existing structure, OCC spreading is not used at this time.

에서 정의되는 cyclic shift

값으로 정의된다. (TS 36.211참조)The ZC sequence is basically the RS

Cyclic shift

Value. (See TS 36.211)

In this proposal, the following basic structure is assumed for the sPUCCH A / N configuration excluding OCC.

Here, PUCCH format 1a / b performs dynamic resource allocation. Basically, the following dynamic allocation is performed based on the CCE index of the scheduled PDCCH.

은 하향 자원 할당에 사용된 DCI 전송에 사용된 PDCCH의 lowest CCE index

와 상위 레이어서 전송되는

에 의해서 결정된다. 여기에서

은 결국 PUCCH format 1a/1b가 다른 PUCCH format 2/3/4 등과 분리될 수 있도록 설정된 일종의 shift 값을 위미한다.Here, the PUCCH resource index for Ack / Nack

The lowest CCE index of the PDCCH used for the DCI transmission used for the downlink resource allocation

And the upper layer

. From here

The PUCCH format 1a / 1b is set as a kind of shift value set so that it can be separated from other PUCCH format 2/3/4 and so on.

The work scope of the recently shortened TTI Work item and the 3GPP RAN WG1 # 86 meeting were further agreed upon as follows.

For Frame structure type 1: [RAN1, RAN2, RAN4]

Specify support for a transmission duration based on 2-symbol sTTI and 1-slot sTTI for sPDSCH/sPDCCH

Specify support for a transmission duration based on 2-symbol sTTI and 1-slot sTTI for sPDSCH / sPDCCH

Specify support for a transmission duration based on 2-symbol sTTI, 4-symbol sTTI, and 1-slot sTTI for sPUCCH/sPUSCH

2-symbol sTTI, 4-symbol sTTI, and 1-slot sTTI for sPTICH / sPTCH

      o Down-selection is not precluded

Study any impact on CSI feedback and processing time, and if needed, specify necessary modifications (not before RAN1 #86bis)

Study any impact on CSI feedback and processing time, and if necessary, specify necessary modifications (not before RAN1 # 86bis)

Agreement:

For FS1,2&3, a minimum timing n+3 is supported for UL grant to UL data and for DL data to DL HARQ for UEs capable of operating with reduced processing time with only the following conditions:

For FS1, 2 & 3, a minimum timing n + 3 is supported for UL grant to UL data and DL data to DL HARQ for UEs capable of operating with reduced processing time with only the following conditions:

A maximum TA is reduced to x ms, where x <= 0.33ms (exact value FFS);

A maximum TA is reduced to x ms, where x < = 0.33ms (exact value FFS);

At least when scheduled by PDCCH

At least when scheduled by PDCCH

For FS2, new DL HARQ and UL scheduling timing relations will be defined

For FS2, new DL HARQ and UL scheduling timing relations will be defined

Details FFS

Details FFS

FFS:

FFS:

Possible minimum timing of n+2 TTI

Possible minimum timing of n + 2 TTI

FFS max TA in this case

FFS max TA in this case

FFS what other restrictions (if any) on when reduced processing times of n+2 could be applied

FFS what other restrictions (if any) on when reduced processing times of n + 2 could be applied

Possibility of scheduling by EPDCCH.

Possibility of scheduling by EPDCCH.

Agreement:

Reduced processing time(s) are RRC configured for the UE

Reduced processing time (s) are RRC configured for the UE

Working assumption: A mechanism for dynamic fallback to legacy processing timings (n+4) is supported

Working assumption: A mechanism for dynamic fallback to legacy processing timings (n + 4) is supported

- Details FFS

Working assumption can be revised if it is not found to be feasible

Additional decisions at RAN1 # 88bis meeting are as follows.

Agreement:

Adopt the following behaviors for the collision of UL grants with n + 3 and n + 4 timing

The UE is not expected to receive conflicting UL grants with N+3 and N+4 timing scheduling PUSCH for the same UL subframe of a carrier

The UE is not expected to receive conflicting UL grants with N + 3 and N + 4 timing scheduling PUSCH for the same UL subframe of a carrier

   - Note: If the UE receives conflicting UL grants with N + 3 and N + 4 timing scheduling PUSCH for the same UL subframe of a carrier, the UE behavior is left up to UE implementation.

Agreement:

For FS1, the UE is not expected to be able to receive UL grants with N+3 and N+4 timing in the same subframe and carrier

For FS1, the UE is not expected to receive UL grants with N + 3 and N + 4 timing in the same subframe and carrier

- Note: This might not imply specification changes

In the current processing time reduction field among the short TTI and processing time reduction items, the problem of n + 3 and n + 4 TTI scheduling on a single terminal basis is handled as an implementation issue. However, the remaining problem is not addressed when n + 3 and n + 4 TTIs are simultaneously scheduled among multiple terminals.

The present invention proposes a solution to the Ack / Nack collision problem occurring in n + 3, n + 4 PDSCH scheduling, which is discussed in the processing time reduction based on 1 ms TTI. Ack / Nack linkage establishment method and specific operation method of PUCCH are proposed so that multiple UEs do not collide upstream Ack / Nack for N + 3 and n + 4 PDSCH at the same time.

It is defined as the existing LTE / LTE-A frame structure (TTI = 1ms = 14 OFDM symbols), and in the field of sTTI and processing time reduction, only the processing time is reduced to the same subframe length. Therefore, we decided to reduce the existing n + 4 based scheduling unit to n + 3.

As a result, linkage collision as shown in FIG. 6 may occur when a plurality of UEs having n + 3 and n + 4 scheduling units are mixed.

In this way, when multiple UEs have different scheduling units, it can be seen that a plurality of A / N resources of the PDSCH are overlapped on one PUCCH. If the processing time reduction PUCCH is designed to maximize the resource allocation principle of the legacy PUCCH that performs A / N transmission, the following PUCCH assignment rule should be utilized.

: 하향 자원 할당에 사용된 DCI 전송에 사용된 PDCCH의 lowest CCE index _-

: Lowest CCE index of PDCCH used for DCI transmission used for downlink resource allocation

: 상위 레이어서 전송되는 shift value _-

: Shift value transmitted from upper layer

가 같아질 수 있는 상황이 발생할 수 있다.Basically, it is assumed that the PDCCH can be transmitted for each TTI (= 1 ms). At this time, UEs having different PDCCH reception intervals can use the same resource allocation index, so that collision of PUCCH resources can occur. That is, the lowest CCE index

Can be the same.

과 같은 shift 값은 cell-specific한 값이기 때문에 셀내 모든 단말이 동일한 값을 가지게 된다 (RRC message). 따라서 sPUCCH의 자원 할당에 있어 충돌이 발생하지 않기 위해서는

이 외에 추가적인 shift 값을 설정해주어야 한다.From here

Is a cell-specific value, all terminals in the cell have the same value (RRC message). Therefore, in order not to cause a conflict in resource allocation of the sPUCCH

Additional shift values should be set.

In this paper, we propose a new N + PUCCH  Allocate resources.

In this proposal, the reuse of the existing PUCCH resource allocation method is presupposed, but the same principle can be applied to other methods. First, based on the above-mentioned PUCCH resource allocation function, the following modified function can be applied.

가 동일하더라도 제안되는 n+3 단말들을 위한 shift 값에 의해서 각 PDSCH의 A/N 전송시 PUCCH 자원은 충돌하지 않게 된다.Here, X _offset is an offset or shift value for solving the problem that n + 3 terminals commonly collide with an existing PUCCH region. That is, the lowest CCE index of the PDCCH detected by each UE

The PUCCH resources do not collide with each other in the A / N transmission of each PDSCH by the shift value for the proposed n + 3 terminals.

Solution 1-1. N + 3 processing time PUCCH  For a resource setting, a specific shift value is RRC With signaling  Setting.

In this proposal, we propose a method of directly setting a specific shift value to the UE with n + 3 scheduling unit by RRC signaling. That is, terminals having n + 3 processing time commonly receive a specific value of X _offset through RRC signaling and receive PUCCH resources using the corresponding information.

=0 이라고 가정한다.For example, it is assumed that the UE # 0 having the n + 4 processing time and the UE # 1 having the processing time of the (n + 3) are transmitted the PDSCH in the suframe # 0 and the subframe # 1, respectively, as shown in FIG. At this time, detection of the lowest CCE index that can be confirmed when each PDCCH is detected

= 0 is assumed.

Through the proposed method, the following sPUCCH resource allocation is performed for each resource. As a result, the sPUCCH resource indexes used by the UE # 0 and the UE # 1 are different and no collision occurs. ( X _offset = 10)

Plan 1-2. N + 3 processing time PUCCH  For a resource setting, a specific shift value is RRC With signaling  And triggering is dynamic With signaling  Setting.

The principle of this proposal is to set a specific shift value through the RRC signaling mentioned above, and means to trigger or not use the corresponding shift value through DL grant.

Accordingly, the eNB can selectively apply the PUCCH resource shift value selectively considering the scheduling environment factor of the n + 3 terminal.

For example, triggering can include a 1-bit information field in a specific DL grant. If the corresponding field value is '1', the UE performs PUCCH resource allocation using the X _offset received from the RRC, and if it is '0', uses the same PUCCH resource allocation procedure.

Methods 1-3. N + 3 processing time PUCCH  For resource configuration DCI  How to use specific fields in information With signaling  And triggering is dynamic With signaling  Setting.

The principle of this proposal is to set RRC signaling as to which information is used as a shift value in DCI information, unlike 'Plan 1-1' and 'Plan 1-2' mentioned above. Here, the RRC signaling may include an antenna port, an HARQ process number, an MCS, a redundancy version, resource allocation information, and a unique RNTI of the UE. Setting. Thereafter, triggering for PUCCH resource allocation using the information can be turned on / off using the DCI information field in the DL / UL grant of about 1 bit.

Methods 1-4. N + 3 processing time PUCCH  For resource configuration DCI  within information PUCCH  Set additional resource fields.

In this proposal, we propose a method to transmit information of sPUCCH resource allocation shift value X _offset through dynamic signaling. Generally, DL grant is used for dynamic signaling. Therefore, the field of the corresponding information should be included in the DCI format for transmitting the PDSCH resource allocation information. Since the information may be large in size, the addition of additional fields in the DCI format may cause a bit limitation or additional overhead.

Specifically, if the PUCCH is included in the existing DCI format, the following modifications are necessary.

DCI format 1As: existing field + shift value field

DCI format 1Bs: Existing field + shift value field

DCI format 2As: existing field + shift value field

... .

The added shift field can be set to 'N' bits, the values are 2, 3, 4 ... And the like.

The present invention proposes a method of preventing Ack / Nack collision between multiple users that occurs when a PDSCH is transmitted in a case where a processing time reduction service is performed in a 3GPP LTE / LTE-A system, and the method is applied to similar signals and channels But it is not limited to the new frame structure.

7 is a diagram illustrating a configuration of a base station according to another embodiment of the present invention.

Referring to FIG. 7, a base station 1000 according to another embodiment includes a control unit 1010, a transmission unit 1020, and a reception unit 1030.

The controller 1010 controls the overall operation of the base station 1000 according to the downlink data channel Ack / Nack collision avoidance method for the sTTI according to the present invention described above.

The transmitting unit 1020 and the receiving unit 1030 are used to transmit and receive signals, messages, and data necessary for carrying out the present invention to and from the terminal.

FIG. 8 is a diagram illustrating a configuration of a user terminal according to another embodiment of the present invention.

Referring to FIG. 8, a user terminal 1100 according to another embodiment includes a receiving unit 1110, a control unit 1120, and a transmitting unit 1130.

The receiving unit 1110 receives downlink control information, data, and messages from the base station through the corresponding channel.

In addition, the controller 1120 controls the overall operation of the user terminal 1100 according to the above-described method of preventing downlink data channel Ack / Nack collision for the sTTI according to the present invention.

The transmitter 1130 transmits uplink control information, data, and a message to the base station through the corresponding channel.

The standard content or standard documents referred to in the above-mentioned embodiments constitute a part of this specification, for the sake of simplicity of description of the specification. Therefore, it is to be understood that the content of the above standard content and portions of the standard documents are added to or contained in the scope of the present invention.

Appendix

[1] Ericsson, Huawei, "New SI proposal Study on Latency Reduction Techniques for LTE", RP-150465, Shanghai, China, March 9-12, 2015.

[2] R2-155008, "TR 36.881 v0.4.0 on Study Latency reduction techniques for LTE", Ericsson (Rapporteur)

[3] R1-160927, "TR 36.881-v0.5.0 on Study Latency Reduction Techniques for LTE", Ericsson (Rapporteur)

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

Claims (1)

A method for preventing downlink data channel Ack / Nack collision for a sTTI,
Allocating a PUCCH resource for a terminal having a (N + 4) processing time;
Allocating a PUCCH resource different from the PUCCH resource for the UE having the (N = 4) processing time for the UE having the (N + 3) processing time; And
And setting a specific shift value to RRC signaling for PUCCH resource setting for the terminal having the (N + 3) processing time.

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